Evaluation of the efficacy and safety of conventional and biportal endoscopic decompressive laminectomy in patients with lumbar spinal stenosis (ENDO-B trial): a protocol for a prospective, randomized, assessor-blind, multicenter trial

Table 1 Evaluation schedule

Visit type	Screening	Operation	Follow-up
Visit	1	2	3	4	5	6
Visit week	-4–0 weeks	0–2 days	2 weeks	12 weeks	24 weeks	52 weeks
Visit week			± 5 days	± 4 weeks	± 8 weeks	± 8 weeks
Informed consent	O
Demographics^a	O
Inclusion/exclusion	O
Randomization		O
Operation		O
MRI (or CT)^b	O	O
Simple radiographs	O		O	O	O	O
ODI	O		O	O	O	O
EuroQol 5-dimensions	O		O	O	O	O
VAS	O		O	O	O	O
POSAS				O	O	O
Other surveys^c			O	O	O	O
Adverse events		O	O	O	O	O

MRI magnetic resonance imaging; CT computed tomography; ODI Oswestry Disability Index; VAS visual analog scale for low back pain and radiating pain of the lower extremities; POSAS Patient and Observer Scar Assessment Scale
^aBaseline patient characteristics, including past medical/surgical history, physical examination, and laboratory tests
^bA CT scan will be obtained if MRI cannot be performed
^c Including surgery satisfaction, walking time, and postoperative return to daily life period

ISSN: 1471-2474